Electric switch.



No. 706,581. y Patented Aug. l2, |902. F. A. mERmcK.

ELECTRIC SWITCH.

(Application led .Tune 28, 1901.)

(un Model.)

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UNITED STATES PATENT OFFICE.

FRANK MERRICK, OF .IOHNSTOVBL PENNSYLVANIA, ASSIGNOR, BY

MESNE ASSIGNMENTS, TO VESTINGIIOUSE ELECTRIC AND MANUFAC- TURING COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 706,581, dated August 12, 1902.

Application filed .Tune 26,1901. Serial No. 66,105. (No model.)

vol this specification.

My invention has reference to electric switches,and more particularly to the switches used on electric -railway\ cars, commonly known as canopy switches, although it may be used for other purposes.

The object of the invention is to provide a simple, durable, and efficient switch capable of carrying` and handling a considerable volume of current without injury; and theinvention consists in the novel construction, combination, and arrangement of parts, all as hereinafter described, and pointed out in the appended claims.

In the accompanying drawings, Figure l is a horizontal section of a switch embodying my invention; Fig. 2, a vertical section of the same on the line 2 2 of Fig. l with the handle removed; Fig. 3, a bottom plan view, and Fig. 4. a detail View, of the spring-catch which holds the switch at its open-circuit or olf position.

In the figures the letter A designates the casing or inclosure of the switch, having` a lining c. of insulating material and constructed with vertically-sliding door portions A' at opposite sides, which give convenient access to its interior. Journaled in the top and bottom walls of the casing is a central shaft or spindle B, to the end portions of which within the casing are pinned or otherwise secured upper and lower metallic heads D D', respectively, the lower-head D being also secured by a nut D2, threaded on the shaft. Secured between these two heads is a metallic drum E, having opposite radially-extending contactcarrying wings or arms E'. The upper and lower ends of the drum are electrically separated from the heads D and D by means of blocks or disks E of insulating material and are mechanically connected to the said heads by means of pins f of insulating material, which pass through the blocks or disks F. The drum is also insulated from the shaft or spindle by asleeve II. Secured to the vertical or peripheral edges of the arms or wings E are a plurality of contacts I, there being four contacts on each Wing in the particular switch shown; Ibut the numberwill obviously vary with the size and capacity ol the switch.

K designates spring contact-lingers which are designed to engage the contacts I, the latter in the construction shown being each broad enough for engagement with two of said lingers. There are two sets of these VVingers, one set l'or the contacts on each arm or wing. They are secured to linger boards or strips L, and the fingers of each set are all electrically connected in multiple with each other. The two upper fingers of each set are placed slightly behind the other fingers, so as to remain in engagement with their respective contacts momentarily after the other fingers have broken their engagement, and the top portion of the casing immediately above these upper lingers is formed with vent holes or openings N.

O is the operating-handle, which is rigidly secured to the lower eXteriorly-projecting end portion of the shaft or spindle. This handle is stopped at its on7 position by a lug o on the casing and is held in this position by means of the friction between the contactfingers and contacts. It is stopped and held at its off77 position by means of a springcatch P, Figs. 3 and 4, having a raised lip p, over which the index end of the handle is pushed.

It will be readily seen that the construction provides for a large current-carrying capacity without undue heating and that the switch is a strong and durable one, having no springs or other parts of a nature likely to become deranged orout of order. In opening the switch the current is finally broken at the upper lingers by reason of the fact that, as above stated, these lingers retain their engagement momentarily after the others and practically the entire are is transferred and limited to these fingers. In this manner the remaining ngers are protected and the destructive action of the arc is confined to the upper fingers, which can be readily removed and replaced when necessary. The arc, moreover, is of short duration, being almost immediately broken by the wide opening which is formed between the contacts before the off position is reached. The products of the are escape quickly through the vent-openings at the top. It will also be noted that by finally breaking the current at the upper fingers and limiting the arcs to that portion of the switch I avoid the necessity for as careful insulation as would otherwise be necessary at the handle of the switch.

The fingers and contacts are readily accessible foradjustment, renewal, or repairs by raising the slides A/ at the sides.

I de not wish to limit myself to the details of construction, arrangement, and combination which I have herein shown and described, as it is obvious that various mechanical ehanges may be made therein without departing from the spirit and scope of my invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. In an electrical switch, the combination of an inclosing easing having Vent-openings in one wall thereof, a rotary drum of conducting material journaled in said casing and insulated therefrom, said drum having two sets of contacts, and a set of contact-fingers for connection with each set of said contacts, the lingers of each set being connected in multiple with each other, and those fingers of each set nearest the vent-openings being set to retain their contact engagement longer than the other fingers of each set.

2. In an electrical switch, the combination with a rotary body or drum of conducting material carrying two sets of contacts, of two sets of contact-fingers, one set for engagement with each set of contacts, the fingers of each set being all connected in multiple in the switch-circuit, and means for actuating the said drum, said fingers being so arranged that one or more of each set will retain their contact engagement momentarilylonger than the remaining fingers.

3. In an electrical switch, the combination with a rotary body or drum having two sets of contacts thereon, of two sets of relatively stationary contact-fingers, one set for engagement with each set of contacts,'the fingers of each set being all connected in multiple, and an actuating-handle secured to the shaft or spindle which carries said body or drum, the contact-fingers of each set which are mest distant from the said handle being placed to retain their contact engagement momentarily after the others.

el.. In anelectrical switch, the combination of a easing or inclosure, a shaft or spindle journaled therein, a body or drinn of conducting material seeured to the said shaft and carrying two sets of contacts, relatively stationary fingers for engagement with each set of contacts, the fingers of each set being connected in multiple, and a handle secured to an eXteriorly-projecting end of the shaft or spindle, the wall of the casing at the opposite end thereof from the handle having vent-openings therein, and the contact-fingers adjacent to said openings being set to retain their contact engagement momentarily after the other fingers.

5. In an electrical switch, the combination of a box or casing, a shaft or spindle journaled therein, heads secured to the end portions of said shaft or spindle, a body or drum of conducting material secured to said heads and insulated therefrom and from the shaft or spindle, said body or drum having two radiating contact-carrying wings, a plurality of contact-fingers for engagement with the contaets of said wings, the fingers of each set being connected in multiple, and an actuatinghandle for said shaft or spindle.

In testimony whereof I have affixed my signature in presence of two witnesses.

FRANK A. MERRICK.

Vitnesses:

Conn G. Cox, lf. W. SMITH. 

